Means for lateral guiding of a web of material



. y 1969 E. l. NILSSON 3,442,428

MEANS FOR LATERAL GUIDING OF A WEB OF MATERIAL Filed July 6, 1967 Sheet of 4 r1 Fig.10

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MEANS FOR LATERAL GUIDING OF A WEB OF MATERIAL Filed July 6, 1967 Sheet 2 of 4 INVENmR Erliha Ingmar Nilsson ATTORNEYS y 6, 1969 E. I. NILSSON 3,442,428

MEANS FOR LATERAL GUIDING OF A WEB OF MATERIAL Filed July 6, 1967 Sheet 3 of 4 Fig.2 4

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ATTORNEYS E. 1. NILSSON 3,442,428

MEANS FOR LATERAL GUIDING OF A WEB OF MATERIAL May 6, 1969 Sheet Filed July 6, 1967 nvvszv'ma ErLing fhgvwr NiLSson 7 BY M JWK P ATTORNEYS United States Patent 3,442,428 MEANS FOR LATERAL GUIDING OF A WEB OF MATERIAL Erling Ingvar Nilsson, Lund, Sweden, assiguor to AB Akerlund & Rausiug, Lund, Sweden Filed July 6, 1967, Ser. No. 651,516

Claims priority, application Sweden, July 27, 1966,

10,211/ 66 Int. Cl. B65h 25/26 US. Cl. 226--19 8 Claims ABSTRACT OF THE DISCLOSURE A lateral guiding means for a running web of material using a pneumatic sensing means to determine the position of the web margin. The sensing means controls the pressure in a pressure box which in turn controls the position of the web margin.

The present invention relates to a device for lateral guiding of a web of material running through a machine for carrying out work operations thereon. In the first place the device is meant to be used in printing presses, cutting machines and laminating machines and for all other kinds of machines where a web of material is transferred from one roll to another and where lateral guiding of the web of material has for a long time been a difficult problem.

The lateral guiding means according to the invention is of the type which comprises a sensing member through which compressed air flows and which determines the position of one margin of the web of material by covering the air passage through the sensing member to a degree corresponding to the said position, a pressure box operated by compressed air for displacing the web of material laterally, and a control valve connected together with the sensing member and the pressure box into a compressed air conduit system in such a way that changes in the fiow of compresed air through the sensing member caused by positional changes of the margin of the web of material will reset the control valve to change the air pressure in the pressure box in such a direction that the latter will return the web of material to its normal position.

The purpose of theinvention is to provide a more reliable device of this kind which operates with greater sensitivity and speed.

The essentially characteristic features of the device according to the invention are that the control valve is a diaphragm valve having on one side of the diaphragm an inlet opening for compressed air from a source of compressed air, an outlet opening provided on the same side of the diaphragm for leading the compressed air to the pressure box, and a duct starting from the same side of the diaphragm and having a choking point for discharging part of the compressed air to the sensing member, and that the diaphragm is operable for controlling the outlet opening and the duct through air pressure acting on the other side of the diaphragm and being variable in dependence on the volume of air discharged through the sensing member, means being provided to open the duct immediately before the outlet opening is opened.

Further objects and advantages of the invention will be apparent from the accompanying drawings showing an embodiment of the device according to the invention chosen by way of example, and where FIGS. 1a and 1b show a basic diagram of the device,

FIG. 2 is a section through a control valve,

FIG. 3 is a horizontal projection from below,

FIG. 4 is a section at right angles to FIG. 3 through a servo valve, and

ice

FIG. 5 is a lateral projection of a sensing member for determining the lateral position of a web of material.

The means according to FIGS. and 1b in the drawings for guiding the lateral position of a web of material 5 running through a machine, e.g. a printing press, a cutting machine or a laminating machine, from one roll to another, is entirely operated by compressed air and consists of a number of apparatus units which are connected into a system of compressed air conduits. The latter is adapted to be connected at 1 directly to a network of compressed air or a compressor, the entering compressed air being first allowed to pass through an air filter 2 of a known kind for separating oft" dirt and water and then through a pressure regulator 3 for reducing the pressure to a value suitable for the operation of the device, e.g. 1 to 1.5 kp./cm. The outlet of the pressure regulator is connected through a pipe conduit 4 to an inlet to a control valve 5 which will be described in greater detail in the following. The control valve has an inlet which is connected through a pipe 6 to an inlet to a servo valve 7, the function and construction of which will also be described in greater detail in the following. A second outlet of the control valve 5 is connected through a pipe conduit 8 to a sensing member which is disposed adjacent onemargin of the web of material and has an outlet aperture for the air supplied, said aperture being almost completely covered, during normal operation, by the marginal portion of the web of material. The sensing member, which is shown entirely symbolically in FIG. 1b in the nature of a plate 9 having an aperture 10, may have different embodiments. An embodiment suitable for thin webs of material is shown in FIG. 5 and will be described below. The servo valve 7 has an outlet which is connected via pipe conduit 11 and via a nonreturn valve 12 with a pressure box .13 provided adjacent one margin of the web of material. This box has a diaphragm 15 which is movable under the action of the compressed air supplied through the pipe conduit 11 and against the action of a return spring '14, and the diaphragm 15 is connected through the intermediary of suitable intermediate members for instance to the roll of material from which the Web of material is rolled 01f or to one or more pulleys over which the web runs and which will guide the web by being in turn guided laterally. The pressure box 13 is also connected directly to the servo valve through a pipe conduit 16 in order to permit the air to return from the pressure box at the displacement of the diaphragm 15 under the action of the return spring 14.

As appears from FIGS. 1a and 2, the control valve 5 has a three-part housing comprising an intermediate part 17 and two outer parts 18 and 19 disposed on opposite sides thereof (in the figures above and below it, respectively). The three parts are held together by means of bolts not shown. Between the intermediate part 17 and the top outer part 18 there is mounted a diaphragm 20, and between the intermediate part 17 and the lower outer part 19 there is mounted an auxiliary diaphragm 21. In the outer part 18 the inlet and outlet openings 22 and 23, respectively, of the control valve are provided for connecting the pipe conduits 4 and 6, respectively, from the pressure regulator 3 to the servo valve 7, respectively. The inlet opening 22 is connected through a short and heavy-duty duct 24 with the interior of the valve housing between the outer part 18 and the diaphragm 20 and between a duct 25 which contains a choking point 26, with the interior of the valve housing at the opposite side of the diaphragm 20. The outlet opening 23 starts directly from the interior of the valve housing above the diaphragm 20 but may under certain circumstances be shut oif because the diaphragm comes to rest tightl against the plane inside of the outer part 18. In the outer part 18 there is further provided a duct 27 which passes from the said plane inside through a filter inset 28 and continues in a duct 29 which is provided in the intermediate part 17 of the valve housing and contains a choking point 30, e.g. of 0.7 mm. diameter, and in a duct 31 in the outer part 19 opening into the chamber in the valve housing defined by the outer part 19 and the auxiliary diaphragm 21. The other outlet opening 32 of the control valve, which is connected through the pipe conduit 8 with the sensing member 9, is provided in the lower outer portion 19 of the valve housing and starts directly from the abovementioned chamber in the valve housing.

The intermediate part 17 of the valve housing contains an intermediate wall 33 dividing the interior of the valve housing between the two diaphragms and 21 into two chambers 34 and 35. Into the upper one 34 of these chambers the above-mentioned duct opens, while the lower chamber 35 is in open connection with the surrounding atmosphere via a duct 36. The two chambers are in connection with each other via a needle valve provided in the intermediate Wall 33 and consisting of a sleeve 37 having a small aperture 38 and a valve needle 39 displaceable in the sleeve. Above the sleeve 37 there is disposed a hood 40 having a laterally displaced aperture 41 for creating an extra pressure drop in the flow path between the two chambers, thus increasing the exactitude of the control which it is intended that the needle valve should carry out and which will be described below.

The upper diaphragm 20, which is adapted to cooperate with the plane inside of the outer part 18 and, as mentioned before, to shut off the outlet opening 23 and also the duct 27 in extreme cases has a washer 44 mounted on its underside by means of a through bolt 42 and a nut 43. The said washer is under the action of a spring 45 disposed centrally between the said washer and the intermediate wall 33, the said spring striving to press the diaphragm 20 to its closing position. The Washer is in the shape of a circular disc having one segment cut away, and is disposed in such a way that its point of gravity or center of gravity lies opposite that part of the inside of the outer part 18 from which the duct 27 starts. The purpose of this is that the movement of the diaphragm in the opening direction under the action of compressed air entering through the duct 24 will always be sure to start exactly opposite the duct 27, which will consequently be opened before the outlet opening 23 is uncovered.

In the lower chamber 35 in the intermediate part 17 of the valve housing there is provided a washer 46 serving to actuate the valve needle 39 and resting on the auxiliary diaphragm 21 and being guided by a cylindrical part of the circumferential wall of the chamber 35. The washer 46 is movable together with the diaphragm between a lower position determined by a pair of support shoulders 47, and an upper position in which it rests against a shoulder 48. In the middle of the washer 46 there is recesesed a rubber cushion 49, which is intended to rest resiliently against the valve needle 39 in order to close the needle valve when the diaphragm moves towards its upper end position.

The servo valve 7 has a housing composed of two parts 50 and 51 between which a diaphragm 52 is mounted. At one side of the diaphragm there is a chamber 53 enclosed by the part 50, while on the other side of the said diaphragm there are provided in the part 51 a central interior recess 54 and an annular low recess 55, which is separated from the recess 54 by an annular valve seat 56 on the inside of the part 51. The valve seat 56 has a plane surface for sealing engagement by the diaphragm 52.

The valve housing part 50 is provided with an inlet opening 57 to which the pipe conduit 6 from the control valve 5 is connected for introducing the compressed air into the chamber 53, and is provided with the outlet opening 58 from which the pipe conduit 11 starts to the pressure box 13. In addition, there is provided a finecalibre outlet opening 59 in the part 50, e.g. having a diameter of 0.7 mm., from the chamber 53 to the atmosphere, for permanent discharge of part of the air supplied from the control valve 5.

In the valve housing part 51 there is provided an inlet opening 60 for connecting the pipe conduit 16 from the pressure box 13. From this inlet opening a duct 61 extends to the recess 54 and a second duct 62 extends to the annular recess 55 in order that the pressure of the air in the pressure box 13 may act on the diaphragm 52 on both sides of the valve seat 56. In the latter there is further provided an annular groove 63 covered by the diaphragm 52 when the latter rests against the valve seat. The groove 63 is connected with the surrounding atmosphere via a duct 64. Into the duct 64 there is introduced a control screw 65 by means of which the duct passage may be choked to the desired degree for permitting a restricted flow of the compressed air coming from the pressure box when the pressure in the said box is sufficiently high to keep the diaphragm away from the valve seat.

At the side of the diaphram 52 which faces the chamber 53 there is fixed a washer 66 by means of a through screw 67 with its retaining nut. Between the washer and the bottom of the valve housing part 50 there is provided a spring 68 striving to keep the diaphragm 52 pressed against the valve seat 56. The screw 67 is bored through in order to put the recess 54 in the valve housing part 51 into connection with the chamber 53 in the part 50, the bore having a choking point 69 of for instance 0.7 mm. diameter.

In order to describe the function of the device it should first be assumed that the web of material to be guided laterally occupies a normal operational position in which its margin 70 (FIG. 1b) covers the aperture 10 in the sensing member 9 partly but not completely. Compressed air entering the control valve 5 from the pressure regulator 3 may act on the top surface (FIGS. 1a and 2) of the diaphragm 20 and keep it at a small distance from the contact surface on the valve housing part 18 against the action of the spring 45. Through the outlet opening 23, the pipe conduit 6, the chamber 53 in the servo valve 7, the pipe conduit 11 and the non-return valve 12, the compressed air acts on the diaphragm 15 in the pressure box 13 and normally balances it against the pressure of the spring 14 at the opposite side of the diaphragm, corresponding to the normal position in a lateral sense of the web of material. As mentioned already, a small part of the compressed air escapes permanently from the servo valve through the opening 59 but is replaced by new air from the control valve 5. From the said valve there flows another small part of the supplied compressed air through the ducts 27 and 29, the choking point 30 and the duct 31 and the chamber below the diaphragm 21 out through the opening 32 and the pipe conduit 8 to the sensing member 9, where it escapes through the uncovered part of the aperture 10.

Already at quite insignificant deviations of the web of material from the normal position the thus arising change of the uncovered area of the aperture 10 causes a change in the escaping air volume. If it increases, the pressure acting on the diaphragm 21 in the control valve 5 will become reduced so that it will move downward and permit the needle valve 37, 39 to open more. Due to the pressure drop arising thereby in the chamber 34, the diaphragm 20 moves downward and lets a greater volume of air pass through the opening 23 and further to the servo valve and therefrom through the non-return valve 12 to the pressure box 13 in order to return the web of material. If the deviation of the web of material takes place in such a direction that the air volume escaping through the aperture 10 is reduced, the pressure on the diaphragm 21 increases, which causes a reduction of the throughfiow in the needle valve 37, 39, an increase of the pressure in the chamber 34 with a consequent motion of the diaphragm 20 upwards, so that a smaller air volume is allowed to escape through the opening 23 to the servo valve and pass on to the pressure box 13. Under the action of the spring 14 of the said box the web of material will then be returned to the normal position. When this is being done the diaphragm 15 presses air back to the servo valve 7 through the air conduit 16, and due to the consequently increasing air pressuer on the top side of the diaphragm 52 (as seen in FIG. la), the said diaphragm leaves the seat 56, whereby the air is allowed to escape through the groove 63, the duct 64 and the control valve 65. In particular if the deviation of the .web of material in the latter case was so great that the aperture in the sensing member was completely covered, the action of the servo valve 7 entails that the returning of the web of material takes place quickly due to the opening of the discharge path through the control valve 65. The device described has, however, a high degree of sensitivity, so that deviations of the web of material in one or the other direction will normally be almost unnoticeably small.

The sensing member 9 may have many different embodiments. FIG. 5 is a mere example of a simple sensing member. It consists of a support plate 71 which is fixed to one end of a tubular shaft 72 and is provided with the aperture 10 not visible in FIG. 5 opposite the end of the bore in the shaft 72. The other end of the shaft is adapted to be connected to the pipe conduit 8. On the top side of the support plate 71 there is-disposed a pressure plate 73 having an aperture opposite the aperture 10, and in order to press the said aperture against the support plate, a spring 74 is provided which surrounds a bolt 75 fixed in the support plate and resting against a nut 76 adjustable thereon. The sensing member may for instance be mounted on a rail, which is part of the machine, by means of a clamp 77 disposed on the shaft 72 in such a position that one marginal portion of the web of material will pass between the plates 71 and 73 partly covering the aperture 10.

The apparatus units described above are merely to be regarded as examples of suitable embodiments, for these units may be embodied otherwise within the scope of the invention.

I claim:

1. Means for lateral guiding of a web of material running through a machine for performing work operations thereon, comprising a sensing member through which compressed air passes, for determining the position of one margin of the web of material by covering the air passage through the sensing member to a degree corresponding to the said position, a pressure box operated by compressed air for lateral displacement of the web of material, and

. a control valve connected together with the sensing member and the pressure box into a system of compressed air conduits in such a way that changes in the flow of com pressed air through the sensing member caused by positional changes of the margin of the web of material will reset the control valve to change the air pressure in the pressure box in such a direction that the latter will return the web of material to its normal position, wherein the control valve is a diaphragm valve having an inlet opening on one side of the diaphrgam for compressed air from a source of compressed air, an outlet opening on the same side of the diaphragm for leading the compressed air to the pressure box, and a duct starting from the same side of the diaphragm and having a choking point for discharging part of the compressed air to the sensing member, and wherein the diaphragm is operable for controlling the outlet opening and the duct by air pressure acting on the other side of the diaphragm and variable in dependence on the outlet of air through the sensing member,

means being provided for opening the duct immediately before the outlet opening is opened.

2. Means as claimed in claim 1, wherein the control valve for producing the air pressure acting on the other side of the diaphragm has a chamber defined by the diaphragm and being in connection with the inlet opening through a narrow duct, and wherein the said chamber is in connection with the surrounding atmosphere through a valve which is controllable by means of an auxiliary diaphragm which is under the action of the pressure of the air discharged to the sensing member, for producing changes in the air pressure acting on the first diaphragm.

3. Means as claimed in claim 2 wherein the means for opening the duct immediately before the outlet opening is opened consists of a washer mounted in the centre of the diaphragm on the side thereof which faces the said chamber, said washer being shaped in such a way that it has areas of different sizes on two opposite sides of the mounting point, the larger area being located opposite that point in the housing of the control valve where the duct discharging compressed air to the sensing member starts.

4. Means as claimed in claim 2, wherein the said valve through which the chamber in the control valve is in connection with the surrounding atmosphere is a needle valve consisting of a stationary member provided in an intermediate wall in the control valve and having a throughfiow aperture and a valve needle actuated by the auxiliary diaphragm.

5. Means as claimed in claim 4, wherein the means for opening the duct immediately before the outlet opening is opened consists of a washer mounted in the centre of the diaphragm on the side thereof which faces the said chamber, said washer being shaped in such a way that it has areas of dififerent sizes on two opposite sides of the mounting point, the larger area being located opposite that point in the housing of the control valve where the duct discharging compressed air to the sensing member starts.

6. Means as claimed in claim 1 wherein there is connected a servo valve between the control valve and the pressure box for bringing about a more rapid return of the web of material to its normal position after such a deviation thereof that the air passage of the sensing member has become completely shut oil.

7. Means as claimed in claim 6, wherein the servo valve is a diaphragm valve which is in connection on one side of the diaphragm with the outlet opening of the control valve and is in connection with the pressure box via a non-return valve and is in connection with the surrounding" atmosphere through a narrow outlet opening for permanent discharge of a small volume of compressed air, and which is in direct connection with the pressure box on the other side of the diaphragm and has an outlet to the surrounding atmosphere which is normally shut off by the diaphragm, said outlet being adapted to be opened under the action of the compressed air in the pressure box in order to bring about a more rapid return of the web of material by discharging the said compressed air.

8. Means as claimed in claim 7, wherein the outlet closed by the diaphragm is controllable by means of a control screw.

References Cited UNITED STATES PATENTS 2,874,961 2/ 1959 Kelly 226-22 3,244,340 4/1966 Fife et a1 22622 ALLEN H. KNOWLES, Primary Examiner.

US. Cl. X.R. 22622 

